Mark 6:3 - Jesus was always referred to as “the” son of Mary, not “a” son of Mary.
Luke 2:41-51 - in searching for Jesus and finding Him in the temple, there is never any mention of other siblings.
John 7:3-4; Mark 3:21 - we see that younger “brothers” were advising Jesus. But this would have been extremely disrespectful for devout Jews if these were Jesus’ biological brothers.
Again, John 19:26-27 - it would have been unthinkable for Jesus to commit the care of his mother to a friend if he had brothers.
John 19:25 - 25Now there stood by the cross of Jesus his mother, and his mother's sister, Mary the wife of Cleophas, and Mary Magdalene. this proves that James and Joseph are Jesus’ cousins and not his brothers: Mary the wife of Clopas is the sister of the Virgin Mary.
Matt. 27:61, 28:1 - Matthew even refers to Mary the wife of Clopas as “the other Mary.”
Matt. 27:56; Mark 15:47 - Mary the wife of Clopas is the mother of James and Joseph.
Mark 6:3 - James and Joseph are called the “brothers” of Jesus. So James and Joseph are Jesus’ cousins yet referred to as "brothers"
Some would even say this as close to Mary Worship you can get. Tch Tch